Exhaust Gas Test (AU) (Audi A4 B5)

In Germany, the first exhaust gas test is required for vehicles with a regulated catalytic converter three years after the date of first approval and then every two years, during which the ignition timing and the efficiency of the catalytic converter are also checked. If an Audi is due for a "major check" at DEKRA or TUV, the exhaust gas test should be carried out first. In our experience, this is done most quickly at certified workshops. In addition, to save time, the Audi workshop always has the latest installation data available, which other workshops, including DEKRA or TUV, receive with some delay.

When checking, the exhaust system must be in working order and there should be no air leaks in the intake manifold. Also, make sure the air filter is clean and the spark plug electrode spacing is correct. In addition, after driving for several months on short distances, it is recommended to change the oil. Fuel condensate that has penetrated the engine oil worsens the exhaust gas parameters.

During the test, the car is connected to an expensive tester in the workshop, the printer of which summarizes the obtained measurement values to confirm the passed test. If individual specified values are not achieved, there is no confirmation of the passed test. Before replacing an expensive unit after a failed exhaust gas test, repeat the test in another workshop. Despite the expensive measuring equipment, there is a scatter in the measurement results. Sometimes a long drive is enough, during which the engine, lambda probe and catalytic converter reach full operating temperature.

The original source of the article can be found on the website AudiManual.ru